Firebox structure



Nov. 1-1, 1941. o. o. VIRDEN FIREBOX STRUCTURE Filed March 13, 1959 INVENTOR ORVILLE O. VIRDEN Z1 ,ZZZ ATTORNEY 4 Patented Nov. 11, 1941 UNITED STATES" PATENT OFFICE rmlllsox STRUCTURE Orville o. Virden, st. Louis, Mo. Application Maren 13, 1939, Serial No. 261,421

4.0laims. ((31.126-451) The invention relates to firebox structure for stoves, ranges, furnaces, boilers, etc.,and consists in a firebox liner constructionproviding for admission of air to a larger portion of the fuel bed than is customary and also facilitating the removal of cinders, ash and other noncombustible elements of the fuel bed.

One object of the invention is to provide complete combustion, particularly of the more volatile elements of the fuel and thereby avoid soot, smoke, etc. 1

Another object of the invention is to.protect the firebox wall from injury by the burning fuel.

'Another object of theinvention is to provide a firebox liner which is easily made and is adapted for different types of fireboxes andis easily installed and removed. a 1

These and other detailed objects "as will be apparent from the following description are attained by the-structure illustrated in the accompanying drawing in which Figure 1 is a vertical section through a or furnace firebox and ash pit.

Figure 2 is a transverse sectiontaken on the line 2-2 of Figure 1 and comprising a top view of the liner structure, a portion of which is broken away to illustrate the support therefor.

Figure 3 is a detailed horizontal section taken on the line 3-3 of Figure 1.

Figure '4 is an isometric view of the backing plate whichforms a detachable member of the liner.

Figure 5 is an isometric view, sectioned in part, of the main grill member of the liner.

Figure 6 is a fragmentary vertical section illustrating the application of the liner to a firebox surrounded by the water leg of the boiler or heater.

Figure 7 is a detailed horizontal section taken on line 1'! of Figure 6.

The stove or furnace illustrated in Figure 1 enlbodies a single outer wall I to which is attached brackets 2 supporting the grate 3 below which is the ash pit 4 and above which is the firebox 5. Also carried on brackets 2 is a sectional ring 6 spaced from wall I and forming a support for the firebox lining.

The liner structure is sectional and comprises a plurality of two part units the main member 1 of which, detailed in Figure 5, forms a grill consisting largely of vertical ribs 8 the sides 9 of which extending transversely of the general plane of the grill and diverge outwardly towards the firebox Wall. Lugs l0 project outwardly from the grill and space the same from the firebox stove wall. The edges ll ofmember"! converge towards th inner face of the member and accordinglywhen the sections are assembled. as shown in Figures 2 and 3 they cannot move away from the firebox wall and become disassembled. Member 1 includes a top ledge 12 extending from the inner faceof the grill to the firebox wall and forming a support for refractory lining l8 and a bafiie for air currents moving upwardly and through the grill as indicated by the arrows A (Fig. 1). m s

Lugs Ill have recesses l3 receiving and seating a solid backing platev I4 positioned between the grill and the firebox wall and serving to protect the latter from too intense heat from the burning fuel; Projections .l! on plate I4 enter and. substantially fill, the space between lugs H] on member 1.

Preferably, liner I4 is ribbed at l6 providing a shallow recess which normally faces the grill andincreases the cross sectional area of space S between the grill and the backing plate. If desired the plate may be reversed, as indicated by the middle section in Figure 3, to accommodate bolts or welds W on the firebox wall.

It is to be understood that a substantial feature of the invention is embodied in'member I independently of the backing plate l4 and in many instances member I can be used without the backing plate, either in the exact form illustrated in Figure 5 orwith details modified such as the elimination of the seats for mounting the backing plate.

Figures 6 and 7 illustrate such a use of member I and show the same applied to a firebox having inner and outer walls 20 and 2I- respectively forming a water leg between them whereby the temperature of the inner wall will be maintained so low that there is little danger of it burning out because of its proximity to the fuel bed. The sectional liner 22 is shown as a duplicate of the liner illustrated in Figures 1 to 5 but backing plate 14 is eliminated. This arrangement could be used in fireboxes of heavy cast metal structure which are not subject to burning out.

The construction described above provides for free circulation of air horizontally around the periphery of the fuel bed and upwardly throughout the heighth of the same thereby bringing fresh air to the upper portion of the fuel bed irrespective of the presence of a substantial amount of fuel, cinders and ash on the grate. Ledge l2 directs air from passage S inwardly through the grills and if a restricted'area of the inlet passage is blocked air has access to the adjacent grill through the lateral passages l9 between the grill and the firebox wall. The air in space l helps to insulate the firebox wall abreast of th liner from being too intensely heated by the burning fuel. Ledge l2 checks the air in space I5 against upward movement along the wall.

The advantageous double wall sectional unit is formed-of castings but the two part assembly simplifies the casting operation and their production involves ordinary open patterns and no cores are required. The small sections can be produced economically and will not be subject to damage from warping, contraction and expan sion as would attend the use of a complete gratelike fire bowl. The sections may be combined in different numbers and arrangements to accommodate different sizes and shapes of fireboxes.

Preferably the discharge of ash, etc., from the fuel bed is facilitated by maintaining the cross sectional area of space S greater than the area of the openings in the grills and by inclining the upwardly facing surfaces 23 downwardly and outwardly as shown.

The grill openings may be circular or of slots disposed horizontally, diagonally and regular or irregular as to size and shape, just so a substantial amount of air can pass through them to the fuel and, preferably, so ash, etc., can pass outwardly to the ash pit.

The variations suggested and. other changes in details may be made without departing from the spirit of the invention and the exclusive use of such modifications as come within the scope of the claims is contemplated.

What is claimed is:

1. A fire box liner comprising a plane-like body having apertures extending substantially throughout its length to form a grill, and having lateral projections for spacing the grill from a fire box wall, the body being provided with seats, a substantially solid backing plate mounted on said seats and spaced from. the grill, the

upright edges of said plate being disposed to contact with the grill and firebox wall. and one side of said plate forming a recess between said edges,said plate being reversible, whereby when said recess faces the grill the width of thespace between the grill and the backing plate will be increased and when said recess faces the firebox wall the clearance between the plate and the wall will be increased to accommodate a projection on the wall.

2. A-fire box sectional liner comprising a flat, thin and relatively wide-plate-like body having a plurality of elongated openings forming a grill substantially throughout the width and length of the body to facilitate the discharge of ash from the inner to the outer face of the body substantially throughout the length and width thereof, there being lateral projections on the outer face of the body for holding the grill spaced from an adjacent fire box wall, said body being substantially free of upwardly facing obstructions on its outer face below the level of the grill and between said projections whereby'ash passing through the grill may drop freely through the bottom of the liner, said projections being provided with recesses, and there being a substantially thin backing plate corresponding in width to. the body and supported insaid recesses and spaced from the grill to form a substantially unobstructed air and ash passageway extending wall, a bracket projecting inwardly from said wall, a ring supported thereon inwardly of said wall to form a substantially unobstructed annular space between. said wall and ring, a plurality of .liner sections mounted edge to edge upon said ring and each comprising a flat, thin and relatively wide body and each forming a vertically disposed grill and having elements holding the upper and lower portions of the grill spaced from said wall, the opposing edgesof said sections flaring outwardly of the firebox to hold said sections against movement away from said Wall, there: being substantially solid backing plates supported in saidsections between the box wall and the grills and spaced from the latter to protect the wall from being burned out by the 'heat from the fuel bed retained by the liner.

ORVILLE O. VIRDEN. 

